I suggest to tell them that we already know the problem: DRM. This is not a question of which software is used, this is a question of the very existance of DRM in that document.
PDFs are great, provided they are made without DRM and that they are in the PDF/A-1 standard, so I would suggest them to stay with PDF, in PDF/A-1 standard. However, most users don't know how to generate PDFs compliant with PDF/A-1 in Microsoft and Adobe software, because the users aren't instructed/taught on how to do so. Even so, I'm unable to tell how to do so in these software, specially because these are non-free software, and we shouldn't teach usage of non-free software ([[https://www.gnu.org/education/education.html]]). If they are thinking about "another way" of providing the application form, I hope they make it into a .odt (OpenDocument Text), .ott (OpenDocument Text Template) or a simple HTML + CSS form (no JavaScript).
